It is well known that aldehydes can be reduced to corresponding alcohols. However, while the catalytic reduction of saturated aldehydes generally proceeds without trouble, difficulties are frequently encountered in selectively reducing unsaturated aldehydes to the corresponding alcohols.
With regard to alpha, beta-unsaturated aldehydes, the selective reduction of the formyl group is made even more difficult by the propensity of the carboncarbon double bond, adjacent to the formyl group, to be simultaneously hydrogenated. Still greater difficulties are encountered when, besides the alpha, beta-unsaturated double bond, additional, reducible, doubleor triple-bonds, which may be conjugated, and/or other reducible groups are present in the aldehyde.